Question

find: a) (f+g)(x) b) (f-g)(x) c) (fg)(x) d) (f/g)(x)
what is the domain of f/g?
f(x)=x/x+1 g(x)=x^3

Answer 1

Right, we'll try this out. Slowly.

Answer 2

can you substitute (f+g) with the actual functions?

Answer 3

a)x^4/(x+1) +1

Answer 4

a: ((x/x+1)+(x^3))(x)
Distribute the outside x.
x^2/x+1 + x^4

Answer 5

b) We're going to replace f and g again.
(f-g)(x)
((x/x+1)-(x^3))(x)
Distribute again.
x^2/x+1 - x^4

Answer 6

Can you handle part C now?

Answer 7

Give it a try.

Answer 8

excuse me mate is it like that (f+g)(x) should be f(x)+g(x)

Answer 9

so it should be just x/(x+1)+x^3 for the question a

Answer 10

Ohh haha. Yes. That does make sense. I didn't even think to consider she was saying f plus g OF x. I was just doing multiplication.

Answer 11

No no, ignore me. That is right. What was I thinking.

Answer 12

b) f(x) - g(x)
Therefore x/(x+1) -x^3
(x-(x^3(x+1)))/(x+1)
(x-x^4-x^3)/(x+1)

Answer 13

c)f(g(x))
x^3/(x^3+1)
because we are substituting x^3 in the function f(x)

Answer 14

did u understand c jane

Answer 15

d) f(x) / g(x)
(x/(x+1))/x^3)
1/(x^2(x+1))

Answer 16

domain for the question is all real values of x excluding 0 and -1, because if we put 0 or -1 for x then f(x)/g(x) would become infinity since we get a 0 in the dinominator

Answer 17

that's all,its easy

Answer 18

Yes easy